Rockitansky

Hi all, I have a 2002 manual trans corvette with 2002 PCM, LS3 stock engine and LS2 throttle body. I got a few codes P1220 Throttle Position Sensor 1 circuit and so on. At track after about 5 laps car would go into limp mode.

Put the Tech2 on it and got these readings. These are my readings with IGN ON only.
It appears my 0% throttle on TPS sensor 1 is too HI at 1.35volts, but within parameters at WOT at 4.45v.
LS2 TB TPS sensor 1 limits are 0% throttle 0.13v to 0.67v.

My TPS sensor 2 reads 3.67v at 0% throttle, which is too LOW. And WOT reads 0.57v which is within limits.
LS2 TB TPS sensor 2 limits are 0% throttle 4.30v to 4.80v.

Now with ENG running the TPS 1 readings go down to 0.86v at 0% throttle but still too HI by about 0.20v.

Could this cause a Limp mode or other problems? And if so any recommendations on how to fix this?
I have no current DTCs using Tech2, I only got the DTCs when on track romping on it hard.
Battery volts read 13.6 v. THX ALL Brian!


Ignition ON:

IGN ON

Running


ENG RUNNING

TB Voltages

AJG87

iTrader: (43)

Just wondering - Are you using a true GM OEM LS2 unit? I've only ever heard a handful of the OEM units faulting.

Rockitansky

Yes its a real OEM GM TB. I even tried another GM TB on my car and got same voltage readings. Car does have a 10% underdrive pulley so alternator is turning slower, but alt still puts out 13.6v at idle. I am thoroughly confused.....